The present invention generally relates to ear plugs for the protection of human hearing, and more particularly, to a hearing protection ear plug that can be easily switched between a position which provides substantial hearing protection and a second position that permits normal sound transmission.
Resilient foam ear plugs are widely used to provide hearing protection. A cylindrical foam earplug may be compressed and inserted into the ear canal, where it expands and conforms to the ear canal. In its expanded position, this foam earplug provides a high level of hearing protection. The “foam” used in these ear plugs (and as the term “foam” is broadly used in this application) can constitute one of many possible soft resilient materials, including silicone, neoprene, polyvinyl chloride, polyurethane, and others. Foam ear plugs are effective both as a result of the sound attenuation properties of the foam and the complete closure that results from expansion of the foam to contact the entire circumference of the ear canal. It is important for the effectiveness of this ear plug that it remains firmly positioned within the ear canal in its expanded configuration.
Hearing protection is needed in situations such as firearm shooting activities and industrial settings where there may be periods of loud noise followed by periods of no noise in which normal conversation is desirable. With prior art foam ear plugs, however, conversation is very difficult because of the high level of sound attenuation afforded by the ear plug. To permit more normal conversation the ear plug must be removed, then recompressed and reinserted into the ear canal before loud noises are again encountered. In any situation in which a user's hands may become dirty (such as in handling a firearm or in an industrial workplace setting) the recompression of the earplug for reinsertion into the ear can result in contamination of the surface of the earplug and transfer of that contamination to the ear canal of the user.
U.S. Pat. No. 7,182,087 describes a two position hearing protector that provides substantial sound attenuation and hearing protection in one position, and in a second position allows sounds to enter the ear of the user relatively unobstructed. That patent describes a mechanical switching mechanism for switching the ear plug from the open to closed position. The present invention is an improvement on the hearing protector of U.S. Pat. No. 7,182,087 and provides a novel and advantageous internal mechanism for switching between the sound attenuating and non-sound attenuating positions of the ear plug.